1. Field of the Invention
One or more embodiments of the present invention relate to a thin film depositing apparatus for generating a process gas of a deposition source and depositing the process gas on a surface of a substrate, and more particularly, to a thin film depositing apparatus for performing a deposition process by reciprocating with respect to a deposition source and a thin film depositing method used by the thin film depositing apparatus.
2. Description of the Related Art
A deposition process whereby a process gas generated from a deposition source is deposited on a surface of a substrate is widely used in a thin film manufacturing process, such as a thin film transistor manufacturing process of an organic light-emitting display device.
Recently, an atomic layer deposition (ALD) process, whereby a thin film may be more uniformly and precisely formed, has been preferred. In such an ALD process, deposition is repeatedly performed at the same location on a substrate more than 300 times.
Thus, to perform such a repetitive deposition process, a scan-type deposition process where a substrate is mounted on a transfer shuttle in a deposition chamber and reciprocates with respect to a deposition source is used.
In general, auxiliary plates having the same size as that of a mounting unit for the substrate are attached to the front and rear parts of the transfer shuttle. The auxiliary plates alternately close a process gas outlet whenever the substrate passes the process gas outlet of the deposition source, which is positioned in the deposition chamber. For example, when the substrate mounted on the transfer shuttle is transferred in one direction, the auxiliary plate at the front part of the transfer shuttle closes the process gas outlet before the substrate enters the process gas outlet of the deposition source, and then, after the substrate passes the process gas outlet, the auxiliary plate at the rear part of the transfer shuttle closes the process gas outlet. That is, the auxiliary plate at the front part of the transfer shuttle, a mounting plate of the transfer shuttle, and the auxiliary plate at the rear part of the transfer shuttle are alternately positioned in front of the process gas outlet of the deposition source, by reciprocating across the front of the process gas outlet.
As described above, the process gas outlet is alternately closed by the auxiliary plates. This is because a state of a process gas of the deposition source is maintained constant while a deposition process is performed. If the auxiliary plates are not used, the process gas outlet is in a completely opened state before and after the transfer shuttle passes the process gas outlet, and thus, the inside of the deposition chamber may be severely contaminated by the process gas of the deposition source. To prevent such a contamination, a separate shutter can be installed at the deposition source so that a process gas is discharged only when a substrate on the transfer shuttle passes the process gas outlet, which leads to less contamination to surroundings. However, a state of the process gas discharged from the process gas outlet is not maintained constant, and thus, this cannot ensure a uniform deposition quality. Therefore, the auxiliary plates are installed at the transfer shuttle so as to constantly discharge the process gas of the deposition source and alternately close the process gas outlet.
However, when the auxiliary plates are installed at the front and rear parts of the mounting plate of the transfer shuttle, the size of a deposition chamber needs to be increased corresponding to the size of the auxiliary plates. That is, since the auxiliary plates having almost the same size as that of the mounting plate are installed at the front and rear parts of the transfer shuttle, a sufficient space for a reciprocating operation needs to be secured, considering the sizes of the transfer shuttle and the auxiliary plates, and the size of the deposition chamber also needs to be increased corresponding thereto.
Therefore, there is a need to develop a method of effectively decreasing the size of a deposition chamber by using auxiliary plates.